Bridging veins at the craniocervical junction: from anatomy to clinical significance in dural arteriovenous shunts.

PURPOSE: Bridging veins (BVs) serve as a route of pial venous reflux, and its anatomy is essential to understand the pathophysiology of dural arteriovenous shunts (dAVSs) around the craniocervical junction (CCJ) (from the jugular foramen level to the atlantal level). However, the anatomical variations of the BVs and their proximal connections remained poorly elucidated. This study aimed to radiologically investigate the anatomy of the bridging veins around CCJ and discuss the clinical significance of these BVs in the dAVS. METHODS: We investigated normal venous anatomy of the BVs from the jugular foramen level to the atlantal level using preoperative computed tomography digital subtraction venography in patients undergoing elective neurosurgery. BVs affected by the dAVSs in the same region were also evaluated. The three types of dAVS, craniocervical junction, anterior condylar, and proximal sigmoid sinus, were investigated. RESULTS: We identified six BV groups: superolateral, anterolateral, lateral, posterior, inferolateral, and inferoposterior. The superolateral and inferolateral groups, connected with the proximal sigmoid sinus and suboccipital cavernous sinus, respectively, were the largest groups. Each group has a specific downstream venous connection. The association with dVASs was observed only in the inferolateral group, which was typically the sole venous drainage in most dAVSs at the CCJ. CONCLUSION: We reported detailed anatomy of BVs from the jugular level to the atlantal level, which enhanced our understanding of the pathophysiology of dAVSs in the corresponding region.

Embolization techniques of spontaneous direct carotid-cavernous fistulae: a single-center experience.

PURPOSE: Spontaneous direct carotid-cavernous fistula (CCF) are usually caused by a ruptured carotid cavernous aneurysm. We studied treatment of spontaneous direct CCFs in a single-center cohort of a high-volume tertiary referral center, reporting anatomical details, technical approaches of treatment, and outcomes. METHODS: Adult patients with a spontaneous direct CCF treated between 2010-2022 with follow-up MRI and/or DSA imaging available were retrospectively analyzed. We studied age, sex, clinical presentation, angiographic findings, treatment techniques, outcomes, and complications. RESULTS: Out of 80 patients with CCFs, twelve patients were treated for a non-traumatic direct CCF (15%) in 13 sessions. Median age was 65 years. Two patients had an underlying connective tissue disorder. In 10 cases, the direct CCF was caused by a ruptured cavernous carotid aneurysm. The direct CCFs were treated by endovascular transarterial embolization (10 cases), transvenous embolization (1 case), or surgery (1 case). Selective closure of the shunt was possible in 10 patients. Two patients were treated with parent vessel occlusion (PVO; one endovascular; one surgical, with bypass). Complications occurred in 2 / 12 patients (17%), with permanent morbidity in two patients (17%): trigeminal neuralgia after PVO and new infarct after surgical PVO and bypass. Selective closure of CCF resulted in no morbidity. There was no mortality in our series. CONCLUSION: Spontaneous direct CCFs are caused by rupture of a cavernous carotid aneurysm in most cases. Selective closure of the shunt, usually feasible transarterially with coils, achieves good results. Reconstructive endovascular techniques are preferred to minimize treatment related neurological complications.

Choroidal arterial abnormality in central serous chorioretinopathy.

PURPOSE: To evaluate the choroidal arterial abnormality in central serous chorioretinopathy (CSC). METHODS: Fifty-two eyes from 52 patients with CSC were retrospectively evaluated. Arterial and venous ultrawide-field indocyanine green angiography were merged after color and transparency adjustments to compare the choroidal arterial and venous vasculature. Specifically, we evaluated whether the choroidal arteries directly fill the pachyvessel without interconnection of choriocapillaris (arterial pachyvessel; aPV). Then, the clinical characteristics of patients with and without arterial pachyvessel were compared. RESULTS: Pachyvessel under subretinal fluid was detected in 47 of 52 eyes (90.4%). An arterial pachyvessel was detected in eight of 52 eyes (15.4%). Of those eight eyes with arterial pachyvessel, seven (87.5%) showed sustained staining through the venous phase, suggesting they are arteriovenous shunt, while one eye (12.5%) showed diminished fluorescence in the venous phase, suggesting this pachyvessel was purely an artery. Patients with arterial pachyvessel experienced more CSC recurrences (non-aPV group: 2.09 ± 1.44 times vs. aPV group: 3.25 ± 1.28 times; p = 0.039) and pachychoroid neovasculopathy (PNV) development (non-aPV group: 2.3% vs. aPV group: 37.5%, p = 0.009). CONCLUSION: The presence of arterial pachyvessel in eyes with CSC may represent choroidal circulatory imbalance and focal shear stress to Bruch's membrane, leading to a chronic nature and PNV development.

Spontaneous thrombosis of high flow pediatric arteriovenous fistulae: Case series of two patients and a comprehensive literature review.

Pediatric pial arteriovenous shunts in the brain and spine are challenging to understand because of low incidence, variable presentation, and associations with genetic syndromes. What is known about their natural history comes from reviews of small series. To better understand the natural history and role for intervention, two cases are presented followed by a review of the literature. In the first case, an infant with a prior history of intracranial hemorrhage from a ruptured pial fistula returns for elective embolization for a second pial fistula which was found to be spontaneously thrombosed 2 weeks later. In the second case, a 5-year-old with a vertebro-vertebral fistula, identified on work up for a heart murmur and documented with diagnostic angiography, is brought for elective embolization 6 weeks later where spontaneous thrombosis is identified. In reviewing the literature on pediatric single-hole fistulae of the brain and spine, the authors offer some morphologic considerations for identifying which high-flow fistulae may undergo spontaneous thrombosis to decrease the potentially unnecessary risk associated with interventions in small children.

Evaluating national guideline concordance of recurrent interventions after radiocephalic arteriovenous fistula creation.

OBJECTIVE: Radiocephalic arteriovenous fistulas have been historically perceived as requiring multiple follow-up procedural interventions to achieve maturation and maintain patency. Recent clinical practice guidelines from the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) emphasize a patient-centered hemodialysis access strategy with new maximum targets for intervention rates, potentially conflicting with concomitant recommendations to prioritize autogenous forearm hemodialysis access creation. The present descriptive study seeks to assess whether radiocephalic fistulas can meet the KDOQI guideline benchmarks for interventions following access creation, and to elucidate clinical and anatomic characteristics associated with the timing and frequency of interventions following radiocephalic arteriovenous fistula creation. METHODS: Prospective patient-level data from the multicenter PATENCY-1 and PATENCY-2 randomized trials, which enrolled patients undergoing new radiocephalic arteriovenous fistula creation, was analyzed (ClinicalTrials.govNCT02110901 and NCT02414841). The primary outcome was the rate of interventions at 1 year postoperatively. Incidence rates were calculated, and time to surgical or endovascular intervention following fistula creation was modeled using recurrent event extensions of the Cox proportional hazards model. Confidence intervals at the 95% level were calculated using nonparametric bootstrapping. RESULTS: The cohort consisted of 914 patients; mean age was 57 years (standard deviation, 13 years), and 22% were female. Median follow-up was 707 days (interquartile range, 447-1066 days). The incidence of interventions per person-year was 1.04 (95% confidence interval [CI], 0.95-1.13) overall; 1.10 (95% CI, 0.98-1.21) before fistula use, and 0.96 (95% CI, 0.82-1.11) after fistula use. The most common interventions overall were balloon angioplasty (54.9% of all interventions), venous side-branch ligation (16.4%), and open revisions (eg, proximalization from snuffbox to wrist, 16.4%). The locations requiring balloon angioplasty included the juxta-anastomotic segment (51.7% of angioplasties), the outflow vein (29.2%), the inflow artery (14.8%), the central veins (3.8%), and the cephalic arch (0.5%). Common indications were to restore or maintain patency (75.6% of all interventions), assist maturation (14.9%), improve depth (4.4%), or improve augmentation (3.0%). In the multivariable regression analysis, female sex (adjusted hazard ratio [HR], 1.21; 95% CI, 1.05-1.45), diabetes (HR, 1.21; 95% CI, 1.01-1.46), and intraoperative vein diameter <3.0 mm (vs ≥4.0 mm: HR, 1.33; 95% CI, 1.02-1.66) were associated with earlier and more frequent interventions. Patients not on hemodialysis at the time of fistula creation underwent less frequent interventions (HR, 0.69; 95% CI, 0.59-0.81). CONCLUSIONS: Patients with radiocephalic arteriovenous fistulas can expect to undergo one intervention, on average, in the first year after creation, which aligns with current KDOQI guidelines. Patients already requiring hemodialysis, female patients, patients with diabetes, and patients with intraoperative vein diameters <3.0 mm were at increased risk for repeated intervention. No subgroup exceeded guideline-suggested maximum thresholds for recurrent interventions. Overall, the results demonstrate that creation of radiocephalic arteriovenous fistula remains a guideline-concordant strategy when part of an end-stage kidney disease life-plan in appropriately selected patients.

Inflow Artery Aneurysmal Degeneration After Long Term Native Arteriovenous Fistula for Haemodialysis.

OBJECTIVE: Inflow arterial aneurysms are a rare but serious complication after long term arteriovenous fistulae (AVF), probably due to arterial wall remodelling after an increase in flow and shear stress, and kidney transplantation with immunosuppressive therapy. This study aimed to describe the outcomes of surgical treatment and long term follow up in a large cohort. METHODS: This prospective cohort study collected data from patients with a true inflow artery aneurysm after AVF creation that was surgically repaired between 2010 and 2022. Anastomotic and infected aneurysms or post-puncture pseudoaneurysms were excluded. Demographic data, access characteristics, symptoms, treatment strategies, and long term follow up were recorded; patency was estimated using Kaplan-Meier survival analysis. RESULTS: During the study period, 28 patients (64% men, mean age 60.1 years) were treated surgically for aneurysmal degeneration of the axillary or brachial (n = 23) or radial (n = 5) artery after an AVF (10 distal, 18 proximal) performed a mean of 18.3 ± SD 7.9 years previously. Most AVFs were ligated or thrombosed, while all patients except one had previously received kidney transplants. Most of the cases (n = 18) were symptomatic: 13 with pain or swelling, four with distal embolisation, and one rupture. They were repaired by aneurysm partial excision and graft interposition (11 great saphenous vein, six ipsilateral basilic vein, three cephalic vein, and two PTFE graft), ligation (n = 3), or direct end to end anastomosis (n = 3). No major complications occurred before discharge, after a mean hospital stay of 2.4 days. After a mean follow up of 4.8 ± 3.3 years, three cases presented complications: two recurrent proximal brachial aneurysms were repaired with an additional proximal interposition graft (one with further late infected pseudoaneurysm) and an asymptomatic post-traumatic graft thrombosis. Five year primary and secondary patency was 84% and 96%, respectively. CONCLUSION: Aneurysmal degeneration of the inflow artery is an unusual complication during long term follow up of AVFs. Aneurysm excision and, in general, autogenous graft interposition using the saphenous or ipsilateral arm vein is a safe and effective strategy.

Remodeling of venous drainage after the treatment of dural sinus malformation with arteriovenous shunts in a neonate: a case report and literature review.

Dural sinus malformations (DSMs) are rare congenital vascular diseases characterized by a giant venous pouch with or without arteriovenous shunts. We present a neonatal case of DSM that was diagnosed prenatally and treated via endovascular intervention in the early postnatal period. The patient presented with a large DSM involving the torcular Herophilion prenatal magnetic resonance imaging (MRI). Enlargement of the head circumference and respiratory failure rapidly progressed after birth. On the 5th day after birth, the neonate underwent endovascular occlusion via the umbilical artery. The arteriovenous shunt was occluded, and the reflux from the enlarged venous pouch to the dural sinus was decreased. No additional procedure other than ventriculoperitoneal shunting was required. The neonate's development slowly caught up to normal parameters. Follow-up MRI demonstrated the successful development of the venous drainage system. DSMs are characterized by an abnormally dilated dural sinus, which can block the venous return and ultimately increase intracranial pressure and cerebral ischemia. Long-term follow-up indicates that an abnormally developed dural sinus can be reconstructed by appropriate and timely treatment.

Filum terminale arteriovenous shunt with nidus structure: a report of rare condition and treatment consideration.

BACKGROUND:  In the literature, filum terminale arteriovenous shunts (FTAVSs) always feature a single shunt point. Nidus-type FTAVSs have rarely been reported, and the best treatment strategy is unclear. This is a report of one exceptional case of a nidus-type FTAVS and surgical treatment of the lesion. CASE DESCRIPTION: The patient suffered from cauda equina syndrome for 9 months. Magnetic resonance imaging and spinal angiography revealed a nidus-type FTAVF at the L2 level. Surgical resection was performed in the hybrid operating room, and the nidus was completely resected with the assistance of intraoperative methylene blue angiography and neurophysiological monitoring. The postoperative neurological function was stable. CONCLUSIONS: A nidus-type arteriovenous shunt could originate from the FT, and in such cases, complete surgical resection with intraoperative neurophysiological monitoring in a hybrid operating room should be suggested.

[Iatrogenic femoral AV-fistula].

The common femoral artery is a widely used for access in endovascular interventions. Various complications, such as hematoma, pseudoaneurysm and AV-fistula (AVF), can arise from arterial punctures with estimated prevalence between 1-10%. AVF is a rare complication with prevalence p<1%. AVF can cause a hemodynamic change in the form of a arteriovenous shunt (AV-shunt). AV-shunts in the groin are usually small and asymptomatic but tend to be symptomatic with larger and persistent AVFs which can present with leg claudication or high outpute heart failure.

Readmissions Following Arteriovenous Access Creation for Haemodialysis in a French National Database.

OBJECTIVE: There is a lack of large real world data on arteriovenous (AV) access results. This study aimed to describe the required hospital care during the first year following creation of AV access. METHODS: Data from all adult patients who underwent creation of AV access performed in 2017 in a public or private facility were collected through the French national hospitalisation database. Patients were classified into two groups ("de novo" and "secondary") according to their history of prior AV access creation. The primary outcome was the proportion of patients with at least one hospital readmission related to the AV access recorded during the first 12 post-operative months. RESULTS: In 2017, 10 476 adult patients underwent AV access creation in France, including 8 690 (83%) de novo creations. An AV fistula was created for 92% of the patients (95% de novo vs. 78% secondary; p < .001). During the first 12 post-operative months, 6 591 (63%) patients recorded at least one related readmission (68% secondary vs. 62% de novo; p < .001). A total of 5 557 (53%) recorded a readmission for surgical/interventional procedure and 2 852 (27%) were observed with a readmission for medical complications. The mean (± standard deviation) number of related readmissions at 12 months was 1.4 ± 1.6 per patient (1.7 ± 1.9 secondary vs. 1.3 ± 1.5 de novo; p < .001). Patients with an AV graft were more frequently readmitted than those with an AV fistula (1.8 ± 2 vs. 1.3 ± 1.5 readmission; p < .001). CONCLUSION: This study highlights the high frequency of readmissions during the first 12 months following creation of AV access, particularly in patients who had already undergone creation of a previous AV access or had an AV graft implanted. Further research should focus on tailoring AV access strategies to improve patient quality of life and decrease the healthcare cost burden.

The efficacy and deficiency of contemporary treatment for spinal cord arteriovenous shunts.

Contemporary treatments for spinal cord arteriovenous shunts are only based on clinicians' treatment experiences and expertise due to its rarity. We reviewed the clinical course of the largest multicentred cohort to evaluate the efficacy and deficiency of contemporary interventional treatments for spinal cord arteriovenous shunts. The clinical features, treatment results and clinical outcomes of 463 patients with spinal cord arteriovenous shunts were retrospectively assessed. The main outcome was the neurological deterioration that was evaluated based on the modified Aminoff and Logue scale. According to post-treatment digital subtraction angiography, complete obliteration was defined as disappearance of the intradural lesion, whereas partial obliteration was defined as any residual intradural lesion remaining visible and was further categorized as shunt-reduction obliteration (the nidus or shunt points were reduced) or palliative obliteration (only obliterated aneurysms or feeders). Cure rate was 40.6% for the whole cohort, 58.5% after microsurgery, and 26.4% after embolization. The curative resection was associated with non-metameric lesions, lesions with a maximum diameter <3 cm and lesions without anterior sulcal artery supply. The curative embolization was associated with fistula-type lesions, non-metameric lesions, and main drainage diameter <1.5 mm. The permanent treatment-related neurological deficits rate was 11.2% for the whole cohort, 16.1% after microsurgery, and 5.6% after embolization. The pretreatment clinical deterioration rate was 32.5%/year, which decreased to 9.3%/year after clinical interventions. Following partial treatment, the long-term acute and gradual deterioration rates were 5.3%/year and 3.6%/year, respectively. The acute deteriorations were associated with metameric lesions, craniocervical lesions, lesions with a maximum diameter ≥2 cm and residual aneurysm. Residual aneurysm was the only predictor of acute deterioration for non-metameric spinal cord arteriovenous shunts. The gradual deteriorations were associated with palliative obliteration, absence of pretreatment acute deterioration and intact main drainage. Although clinical risks of spinal cord arteriovenous shunts were reduced following clinical interventions, contemporary treatments for spinal cord arteriovenous shunt remains associated with considerable risks and incomplete efficacy. Individualized treatment plans should be adopted according to the angio-architectural features and major clinical risks of specific lesions. There is a higher opportunity for complete obliteration for lesions with simple angio-architecture. However, for most of spinal cord arteriovenous shunts with complex vascular anatomy, partial treatment is the only choice. For these patients, palliative obliteration targeting the aneurysms is recommended for reducing haemorrhagic risk, whereas shunt-reduction obliteration is necessary for non-haemorrhagic myelopathy. Contemporary treatment is ineffective in reducing haemorrhagic risk of incurable metameric spinal cord arteriovenous shunts.

Complication rate, cure rate, and long-term outcomes of microsurgery for intracranial dural arteriovenous fistulae: a multicenter series and systematic review.

Although microsurgery is an established treatment modality for intracranial dural arteriovenous fistula (dAVF), data regarding the perioperative complication rate, cure rate, and long-term outcomes remain scarce. The aims of this study were to describe our original experience with microsurgery, including the surgical complications and pitfalls, and conduct a systematic review of the relevant literature. A multicenter cohort of patients with dAVF treated by microsurgery was retrospectively assessed. In addition, the PubMed database was searched for published studies involving microsurgery for dAVF, and the complication rate, cure rate, and long-term outcomes were estimated. The total number of patients in our multicenter series and published articles was 553 (593 surgeries). The overall rates of transient complications, permanent complications, death, and incomplete treatment were 11.4, 4.0, 1.2, and 6.5%, respectively. A favorable outcome was achieved for 90.1% patients, even though almost half of the patients presented with intracranial hemorrhage. Of note, the incidence of recurrence was only one per 8241 patient-months of postoperative follow-up. Surgeries for anterior cranial fossa dAVF were associated with a lower complication rate, whereas those for tentorial dAVF were associated with higher complication and incomplete treatment rates. The complication and incomplete treatment rates were lower with simple disconnection of cortical venous drainage than with radical occlusion/resection of dural shunts. Our findings suggest that the cure rate, complication rates, and outcomes of microsurgery for dAVF are acceptable; thus, it could be a feasible second-line treatment option for dAVF. However, surgeons should be aware of the specific adverse events of microsurgery.

Racial and Sex Disparities in Catheter Use and Dialysis Access in the United States Medicare Population.

BACKGROUND: Despite efforts to increase arteriovenous fistula and graft use, 80% of patients in the United States start hemodialysis on a central venous catheter (CVC). METHODS: To better understand in incident hemodialysis patients how sex and race/ethnicity are associated with time on a central venous catheter and transition to an arteriovenous fistula and graft, our observational cohort study analyzed US Renal Data System data for patients with incident ESKD aged ≥66 years who started hemodialysis on a CVC in July 2010 through 2013. RESULTS: At 1 year, 32.7% of 74,194 patients transitioned to an arteriovenous fistula, 10.8% transitioned to an arteriovenous graft, 32.1% stayed on a CVC, and 24.5% died. Women spent a significantly longer time on a CVC than men. Compared with white patients, patients who were black, Hispanic, or of another racial/ethnicity minority spent significantly more days on a CVC. In competing risk regression, women were significantly less likely than men to transition to a fistula and more likely to transition to a graft. Compared with white patients, blacks were significantly less likely to transition to a fistula but more likely to transition to a graft, Hispanics were significantly more likely to transition to a fistula, and other races/ethnicities were significantly more likely to transition to either a fistula or a graft. CONCLUSIONS: Female patients spend a longer time on a CVC and are less likely to transition to permanent access. Compared with white patients, minorities also spend longer time on a CVC, but are more likely to eventually transition to permanent access. Strategies to speed transition to permanent access should target groups that currently lag in this area.

Natural history of spinal cord arteriovenous shunts: an observational study.

The natural history of intradural spinal cord arteriovenous shunts is unknown. We performed an observational study in a consecutive patient cohort with symptomatic intradural spinal cord arteriovenous shunts who were admitted to three institutes to investigate the clinical course of this complex disease, which would provide valuable evidence to inform clinical decision-making. The clinical course of patients with symptomatic intradural spinal cord arteriovenous shunts from initial presentation to occurrence of clinical deterioration, initiation of treatment, or last follow-up was analysed. Patients with at least 1 month of observation were included in this study. Clinical onset and deterioration patterns were divided into acute and gradual. Annual and cumulative rates of clinical deterioration as well as their risk factors were analysed using Kaplan-Meier life table analysis and Cox proportional hazards model. To assess risks and benefits of treatment, post-treatment clinical courses were further assessed. Four hundred and sixty-six patients with a mean observational period of 36.9 ± 58.8 months were included; 56.7% of patients presented with acute onset, of whom 77.3% experienced spontaneous recovery. Age of onset older than 28 years, initial modified Aminoff and Logue scale of >3, mid-thoracic lesions and non-ventral lesions were independent predictors of failure for spontaneous recovery. The annual risk of general, acute and gradual clinical deterioration after onset was 30.7%, 9.9% and 17.7%, respectively. Risk of deterioration was highest in the early period after initial onset. Acute onset was the only independent risk factor [hazard ratio 1.957 (95% confidence interval, CI 1.324-2.894); P = 0.0008] of acute deterioration and gradual onset was the strongest predictor [hazard ratio 2.350 (95% CI 1.711-3.229); P < 0.0001] of the gradual deterioration among all the stratifying factors. After invasive treatment, complete obliteration was achieved in 37.9% of patients (138 of 364) and improved or stable clinical status was noted in 80.8% of patients. Forty-two patients (11.5%) experienced permanent complications. Overall post-treatment deterioration rate was 8.4%/year, and 5.3%/year if permanent complications were excluded. The natural history of symptomatic spinal cord arteriovenous shunts is poor, especially in the early period after onset, and early intervention is thus recommended. Initial onset pattern significantly affects the natural history of the lesion, which prompts a differentiated treatment strategy.

Quantification of the severity of outflow stenosis of hemodialysis fistulas with a pulse- and thrill-based scoring system.

BACKGROUND: Hyper-pulsatility of hemodialysis arteriovenous fistula (AVF) is the basic physical examination finding when there is outflow stenosis. The arm elevation test can also be utilized to detect outflow stenosis. If there is no significant outflow stenosis, the AVF should collapse, at least partially, because of the effect of gravity when the AVF-bearing arm is elevated to a level above that of the heart. However, if there is significant outflow stenosis, the portion of the AVF downstream of the stenosis will collapse, while the portion upstream of the stenosis will remain distended (Clin J Am Soc Nephro 8:1220-7, 2013). In our daily practice, when performing the arm elevation test, we not only observe the collapsibility of the access outflow but also palpate the outflow to identify a background thrill that sometimes disappears with the arm at rest, only to reappear when the arm is elevated. If there is no thrill upon arm elevation, we assume that the outflow stenosis is severe and refer to this condition as "physical examination significant outflow stenosis" (PESOS). The aim of this study is to characterize PESOS using percentage stenosis and Doppler flow parameters. METHODS: We performed a case-control study using data collected prospectively between June 2019 and December 2019. A pulse- and thrill-based score system was developed to assess the severity of AVF outflow stenosis. We recorded the outflow scores and Doppler measurements performed in 84 patients with mature fistulas over a 6-month period. Angiograms were reviewed to determine the severity of outflow stenosis, which was assessed by calculation of percentage stenosis. RESULTS: Receiver operating characteristic analysis showed that a cutoff value of ≥74.44% stenosis discriminated PESOS from other AVF outflow scores, with an area under the curve of 0.9011. PESOS diagnosed cases with ≥75% outflow stenosis in an AVF, with a sensitivity of 80.39%, a specificity of 78.79%, a positive predictive value of 85.42%, and a negative predictive value of 72.22%. CONCLUSIONS: PESOS can be used to diagnose ≥75% outflow stenosis in an AVF, with or without a significant collateral vein, and its diagnostic accuracy is high. The use of PESOS as an indicator for treatment implies that physical examination may represent a useful surveillance tool.

Outcomes of incisional negative pressure wound therapy following brachiobasilic transposition arteriovenous fistula creation: A 1:2 propensity score matched study.

Incisional negative wound pressure therapy (iNPWT) use on closed incisions has been shown to improve wound outcomes, but no studies have evaluated the use of iNPWT following brachiobasilic transposition arteriovenous fistula (BBT-AVF). We aim to investigate the efficacy of iNPWT vs conventional wound therapy in reducing surgical site infections (SSIs) for BBT-AVF incisions. This is a retrospective cohort study of patients who underwent BBT-AVF creation between January 2010 and December 2017. A 1:2 propensity score matching (PSM) was performed to reduce selection bias and address for confounding factors. Study outcomes included SSI and haematoma incidence, 30-day readmission, and 30-day mortality. A total of 154 patients were reviewed in this study: 47 (30.5%) had iNPWT and 107 (69.5%) had conventional wound therapy. The overall median age was 60.5 (interquartile range 54-69). PSM with a 1:2 ratio resulted in a total of 117 patients (39 iNPWT and 78 conventional wound therapy). In the unmatched cohort, SSI incidence was lower in the iNPWT group (n = 1/47 [2.1%] vs n = 14/107 [13.1%], P = .035). However, incidence of SSI was comparable between iNPWT and conventional wound therapy after matching (n = 1/39 [2.6%] vs n = 9/78 [11.5%], P = .102). There was no significant difference in 30-day readmission and 30-day mortality. Within our study population of patients with BBT-AVF incisions, there is a non-statistically significant reduction in SSI incidence for patients who received iNPWT as compared with conventional wound therapy. Further prospective randomised controlled studies should be conducted to validate these findings.

Detection of the artery of Adamkiewicz using multidetector row computed tomography in patients with spinal arteriovenous shunt disease.

PURPOSE: To plan a treatment strategy for a spinal arteriovenous shunt (SAVS), identifying the artery of Adamkiewicz (AKA) and its origin is indispensable. However, detecting the AKA is very difficult in patients with an SAVS when using computed tomography angiography (CTA) by the usual method to find the hairpin curved artery because dilated drainage veins nearly always coexist with the hairpin curved AKA. We designed a method to identify the AKA by focusing on the diameter and pathway of the anterior radiculomedullary arteries (RMAs). MATERIAL AND METHODS: Seven consecutive patients with an SAVS were surveyed. They underwent contrast-enhanced CTA and conventional angiography from January 2009 to December 2012. Two readers evaluated the CTA images and assumed that the AKA was the artery that ran through the anterior portion of the neural foramen and continued to pass on the ventral side of the spinal cord. RESULTS: Among the seven patients, nine AKAs were detected with conventional angiography. When using our method, seven AKAs and six AKAs were identified on CTA by Reader 1 and Reader 2, respectively. The average sensitivity was 72.3%, and the specificity, accuracy, positive predictive value, and negative predictive value were sufficiently high (i.e. > 85%) for both readers. The kappa value for detecting the AKA was 0.98. CONCLUSIONS: Detecting the origin of the AKA with CTA is challenging in patients with an SAVS. However, focusing on the diameter and pathway of the RMAs may allow successful identification.

Intradural radicular arteriovenous fistula that mimics dural arteriovenous fistula: report of three cases.

We herein present three cases of a rare type of spinal AVF, an intradural radicular AVF, which mimicked a dural AVF. A 65-year-old male presented with congestive myelopathy. On angiography, right vertebral angiogram (VAG) showed a suspected dural AVF; however, left VAG showed the same intradural dilated vein fed by the anterior spinal artery (ASA). Intraoperative and histological results suggested that a single AVF was located on the right C1 nerve root fed by the right C1 radicular artery and branch of the anterior spinal artery. Two additional patients with a radicular AVF at the C3 or C5 level were presented. Intradural radicular AVFs and dural AVFs have very similar appearances; however, there is a difference that makes the risk of the endovascular treatment of radicular AVFs markedly higher because of blood supply from the ASA. In our case, the AVF was completely occluded by direct surgery without major complications.

Hepatopulmonary syndrome-attributed extreme hypoxemia and polycythemia revealing liver cirrhosis.

We report an unusual case of severe hepatopulmonary syndrome with previously unrecognized cirrhosis, presenting with acute on chronic dyspnoea, extreme hypoxemia, secondary polycythemia as well as direct identification of arteriovenous communications on computed tomography angiography. Hepatopulmonary syndrome, defined as the combination of hepatopathy, arterial deoxygenation and pulmonary vascular dilatation, is increasingly recognized as a life-threatening complication in advanced liver disease and transplant candidacy. It is usually diagnosed in chronic liver disease patients following pre-transplant evaluation or mild dyspnea investigation. Diagnosis relies on the indirect evidence of pulmonary arteriovenous communications suggested by echocardiography with a bubble study. Clinicians need to be aware of this rare but potential acute presentation at the emergency room.

Measuring the palpable pulsatility length as a physical examination test in defining the severity of inflow stenosis for hemodialysis fistulas.

BACKGROUND: Pulsatility is an important property of hemodialysis arteriovenous fistulas (AVF) and can be perceived by the fingers as a gradual decrease in strength downstream from the anastomosis along the main trunk of the fistula. The distance from the point at which the pulse becomes imperceptible to the anastomosis is termed the palpable pulsatility length (PPL); we considered this length may play a role in assessing the severity of inflow stenosis for hemodialysis fistulas. METHODS: This study was performed by retrospective analysis of routinely collected data. Physical examinations and fistula measurements were performed in a selected population of 76 hemodialysis patients with mature fistulas during half a year. Fistula measurements included the PPL before and after treatment and the distance between the anastomosis and the arterial cannulation site (aPump length). The aPump index (API) was calculated by dividing the PPL by the aPump length. Angiograms were reviewed to determine the location and severity of stenosis. PPL and API were used to detect the critical inflow stenosis, which indicates severe inflow stenosis of an AVF. RESULTS: Receiver operating characteristic analysis showed that the area under the curve was 0.895 for API and 0.878 for PPL. A cutoff value of API < 1.29 and PPL < 11.0 cm were selected to detect the critical inflow stenosis. The sensitivity was 96.0% versus 80.0% and specificity was 84.31% versus 84.31% for API and PPL, respectively. CONCLUSIONS: PPL and API are useful tools in defining the severity of pure inflow stenosis for mature AVFs in the hands of trained examiners with high sensitivity and specificity.